Here's the originals of the two girls. The hair looks like a bad hair day. Plastic skin? I created a new fill layer with the selected color, set it to the color blend mode, and added a mask filled with white. Any suggestions or better techniques?

They look like you colored parts as one whole color. Take for instance, her hair. Her shadows and highlights are the same color. Remember that when you look at someone, your shadows can be cooler, and your highlights can be warmer, or vice versa. So the girl could have a greyish shadow to her hair, and a blonder, yellower highlight.

You did a good job. I can't say that I could do any better. Having said that, we are all trying to improve, right? To that end, I agree with Swampy, the color looks pasted on.

I know you've seen Vikki Hansen's colorizning work. If you observe her images very, very closely, you'll see that she doesn't use just one color. For example, on the skin there may be several different colors and shades. This gives depth and realism. Just like reality, our skin isn't evenly colored (unless you're a Kabuki actor

There. See? I did need to recalibrate. I just went back to Vikki's site and the difference is clear. Oh well, that's what critiques are all about. I'm still happy that it kind of clicked finally. My earlier ones were horrid!

the hair fringes are off a bit. looks like you extracted or something and didnt quite get it right on the fringes.

the skin is a bit pasty/plastic. and that's always the toughy on these. try adding some noise on the face.

i love how you did the dress. that part seems excellent.

i also dont like the solid vignette on the bottom half. it cuts her arms off and makes her look like an amputee. a soft vignette all the way around would have been better.

i also found a lot of dust type particles in the background. restoring shld always be done fully before colorizing.

i tried the 2nd one also, but just the face and hair. there are over 1000 steps here. and i know that because my undo was set for 1000 and i'm now missing the first steps. i've now placed my undo at unlimited.

basically, flora got me started colorizing a while back. so i always make a blank layer and airbrush on that. then i most often use a guasian blur of about 1 to 10, depending. sometimes i'll add a blend mode to that layer and sometimes not. if i use a blend mode it will be color, overlay, multiply, hard light or soft light. those seem to work best and which one just depends on how each one looks.

i normally do the skin first, sometimes making more than one layer for it. the eyes are on their own layer and the lips are on their own layer. the hair was also done on several layers and i added a hue/sat adjustment layer for the hair only, just so i could tweak it a bit better.

oh, and before i ever started airbrushing, i cleaned up the picture a bit. i also brightened it and added a bit of contrast.

i also tried something new. when i had the skin a pretty good color, i cloned it to a new layer and added noise. i then blurred this very lightly and set the mode to soft light. i did this again later, without the blur and set it to hard light. so, there were two layers of just adding noise to get some skin texture.

the airbrush/gausian blur technique is a great way to learn. it's fairly easy and fairly forgiving. you can slap paint on pretty loosely and liberally and mix and dab and whatever and the blur fills it out and smoothes it around nicely. i then follow that with an eraser to get rid of where it shldnt have blurred to. adding noise after that brings back texture.

i also copy merged and pasted to a new layer several times. this is like giving yourself a new background to work with but with all your new work on this new layer. it's also a good place to save in case of crashes.

near the end, i had a copy merge layer and simply turned off all other layers except the copy merge and the original background and used another blend mode to bring back some detail lost in all the painting. i set the blend mode for this to hard light. and that was pretty much it.